Summary: Atomistic simulations of solid-phase epitaxial growth in silicon
Noam Bernstein* and Michael J. Aziz
Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138
Efthimios Kaxiras
Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138
and Physics Department, Harvard University, Cambridge, Massachusetts 02138
Received 19 October 1999
High-quality semiconductor crystals can be produced by solid-phase epitaxial growth at the amorphous-
crystal interface. Despite extensive experimental studies, the microscopic mechanisms that lead to crystalliza-
tion are not known. Molecular-dynamics simulations of a Si 001 amorphous-crystal interface, using an accu-
rate empirical interatomic potential, give an activation energy for T 950 K and a shape for the activated
state that are in reasonable agreement with experimental measurements. Analysis of the simulations reveals
complex microscopic mechanisms involving one or several consecutive atomic rearrangement steps; the un-
anticipated level of complexity casts doubt on the common viewpoint of a unique mechanism.
Epitaxial crystal growth from the vapor or melt has at-
tracted much attention in recent years, motivated both by a
fundamental interest in understanding growth phenomena
and by the practical goal of controlling and improving
growth of technologically important materials. Epitaxy can
also occur at the amorphous-crystal interface, when the